#include <stdio.h>
#include <math.h>
int number[320];
void main()
{
    int i,j,count=0;
    printf("There are following primes sequences in first now:\n");
    for(j=0,i=3;i<=1993;i+=2)
        if(fflag(i))
            number[j++]=i;
    for(j--;number[j]>1898;j--)
    {
        for(i=0;number[j]-number[i]>1898;i++);
        if(number[j]-number[i]==1898)
            printf("(%d).%3d,....,%d\n",++count,number[i],number[j]);
    }
}
fflag(int i)
{
    int j;
    if(i<=1)
        return 0;
    if(i==2)
        return 1;
    if(!(i%2))
        return 0;
    for(j=3;j<=(int)(sqrt((double)i)+1);j+=2)
        if(!(i%j))
            return 0;
    return 1;
}